Improvement in hydraulic cement



UNITED STATES PATENT OFFICE.

FRANK E. BROWN AND WILFRED L. BROWN, MARE ISLAND, GAL.

IMPROVEMENT IN HYDRAULIC CEMENT.

Specification forming part of Letters Patent No. 154,641, dated September 1, 1874; application riled Y J une 11, 1874.

To all whom it may concern.-

coralline, coral rock, or fossil-coral, never beforeemployed for this purpose.

Similar 'to the ordinary methods of compounding, drying, burning, and grinding the ingredients of chalk, limestone, slaked lime, quicklime, and clay, resulting in the production of hydraulic cements, our process consists in first thoroughly drying the said coralline and the clay required to be used, and then finely grinding or pulvenizing them, together in proportions from seventy-six (76) per cent. to eighty (80) per cent. of the coralline or coral substanc and from twenty-four (24) per cent. to twenty (20) per cent. of the clay, the said proportions being taken by wei ht.

The required proportions may be determinedin the various qualities of the materials employed, either by practical trial of the mixed compound by burning and grinding the same into cement-powder, and afterward testing its quality as a hydraulic cement, or by chemical analysis, according to methods applicable.

to the general practice'of artificial hydrauliccem ent manufacture.

After the corallinc and the clay are finely ground, the compound is to be thoroughly and intimately mixed with sufficient water, either hot or cold, to a plastic state. It is then to be formed into bricks of a size, say, of an ordinary buildingbrick, and set aside for drying either by naturalor artificial heat. The operation of water-mixin g and forming the mixture into bricks may be performed by a machine resembling an ordinary pug-mill, provided with a molding aperture or former, whichwill deliver the mixed compound in a continuous rectangular prism, which maybe out 01f in lengths required for the bricks, the illustration of such-a machine being shown in the ordinary brick-making machine.

' The dried bricks are to be burned in a kiln with a heat sufliciently intense and prolonged to reduce them to a somewhat vitrified condition. When the kiln is sufficiently cooled, the bricks are removed therefrom, broken up and ground in the ordinary manner, in which burned hydraulic limestone istreated for hydraulic cement, the ground material constituin g the powder of artificial hydraulic cement.

The manipulation of our process does not difl'er from the common methods adopted for the manufacture ofartificial hydraulic cements with the well known substances of chalk, limestone, slaked'and caustic limes combined with a suitable clay, and we make no claim to the use of any of these substances or to any of the mechanical operations herein mentioned.

We claim as our invention- The use of corallinc, coral rock, or fossilcoral, as thcsubstance may be called, for the manufacture and production of hydraulic cement.

FRANK EDWARD- BROWN.

WILFRED LANGDON BROWN.

Witnesses:

A. P. Vooannns, T. H. CHANDLER. 

